Filtering compound



' .No Drawing.

UNITED STATES PATENT OFFICE.

LEO 'WASHBURN SKULL, OF TOLEDO, OHIO, ASSIGNOB TO THE ALLEN FILTER COMPANY, OF TOLEDO, OHIO, A CORPORATION OE OHIO.

. surname comrounb.

To all whom it concern v Be it known that I, Lao WASHBURN SHULL, a citizen. of the United States and.

resident of Toledo, in the county of uses and State of Ohio, have invented certain new and useful Filtering Compounds, of which the following is a specification.

The means hitherto employed for filterin water ordinarily consist in the use of burne brick, powdered subst noes, and venous other materials, but wh ch, either from the character of thematerials themselves or from the manner in which they are prepared or compounded, are not satisfactory where great thoroughness in filtering is requisite. However eificient the named substances may be for removing'visible impurities, they do not retain all germs or microbes or extremely small organisms which are held in suspension in the water, or other liquid. as for example, infected blood taken from human beings or animals, or. generally any blood infected with microbes. Such filtering materials are also ineffective for remov ing the destroyed germs from wines, vinears, beer and other like beverages, which ave first been subjected to a certain degree of heat for the purpose of destroying such germs.

My invention is designed more completely to hold back and retain such germs or micro-- organisms, and it consists of a compound to be used for filtering water, wines, beverages and all liquids generally, and specially for obtaining blood serums. v

The compound is formed substantiallyof American or other kieselguhr with a. certain percentage of asbestos, and whiting (or an equivalent as hereinafter named) and treat ed as hereinafter described. a

The kieselguhr is ground to. afine powder in any suitable mill and properly mixed with the other chemicals herein mentioned or their equivalent, and water, and subjected to a high degree of heat in any suitable kiln.

The proportions are from to 80% of kieselguhr, 10 to 30% of asbestos and 10 to 15% of whiting or its e uivalents. These proportions may however e varied more or less thereby varying the porosityilhardness and other properties of the finis ed material. I wish it to be understood that I do not limit myself to the above named sub- Specificatlim of Letters ratent. Patented Apr, 13; 1920, Application. filed November 1, 1916. SeriaLNo'. 128,856.

stances, for ,the same or similar results may This binder. consisting mainly of calcium hydroxid ((3111 0 when subjected" to the high temperature of the fixing process, loses its water and changes to calcium oxid (CaO When the compound is later treated with water this oxid is changed to a hydrate and the greater portion thereof washed away, leaving the highly orous kieselghur, forming the main ingred cut or body of the filter and the asbestos forming a binder.

The above described compound is particularly adapted for filtering liquids under pressure owing to its being porous to a large degree, and for this purpose it may be used with any'suitable filtering apparatus. The, method of manufacturing the filter mg bodies may consist in mixing the ingredients, each in the form of a fine powder, with a small proportion of water added, and then subjecting the mixture to high )ressure, or casting, molding, or turning.

he filtering body thus produced is then baked or burned in a kiln in the usual way. the temperature ranging from 1800 degrees to 3000 degrees Fahrenheit. A higher temperature is fatal as it causes the material to disintegrate and renders it almost useless. A lower temperature is insufficient-t0 cement the material together and properly harden tained is homogeneous and fulfils the reguired conditions for filtering the hereinbeore mentioned substances, and thereby obtaining the results herein specified.

I do not wish to be understood as laying claim, broadly, toethe materials hereinbe- 'fore mentioned as a filtering com ound, but

only when the are combined an treated as above specifien.

V ture of kiese] 25 ture of kiesel is ren cred porous.

2. A filtering compound formed of a mixture of kiesel uhr, asbestos, and whiting, reduced to a so id, porous, homogeneous mass by subjecting the mixture to a temperature between 1800 and 3000 degrees Fahrenheit.

3. A filtering compound formed ofia mixduced to a so id, porous, homogeneous mass by subjecting the mixture to a high temperature, the ingredients being in the proportion of 60 to 80 per cent. ieselguhr, 1-0 to per cent. asbestos, and 10 to 1'5 per cent. whiting.

4. A filtering compound formed of a mixhr, asbestos and whiting, reduced to a so id, porous, homogeneous mass by subjecting the mixture to a higlrtemperahr, asbestos and whiting, re-

, ture, the ingredients being proportioned, so

that more t an half of the mixture is kieselguhr, less than a third is asbestos, and a small amount is whiting. r

5. A filtering compound formed of a mix: ture of kiesel uhr, asbestos and whiting, re-

duced to a so id, porous, homogeneous mass by sub'ectingthe mixture to a high temperature, t e proportion of the ingredients being more than 50% kieselguhr and the remainder asbestos and whiting.

6. Theprocess-of forming a filterin compound which consists in mixing kiese guhr asbestos and 'whiting each in the form of a fine powder, with water added, subjecting the mixture to high pressure, and then firin the mixture at a temperature which wi drive off the water from the calcium hydroxid.

Signed at Toledo in the county of Lucas and i tate of Ohio, this 30th day of October A. 1)., 1916. i

LEO WASHBUR'N SHULL. 

